Press



July 20, 1937 l. PATRICK I 7,

PRESS Filed June 15, 1954 s Sheets-Sheet 3 I g ULM ATTORNEY-5.

Patented July 20, Y 1937 UNITED STATES PATENT OFFICE PRESS Isaac Patrick, Mount Gilead, Ohio, assignor, by.

mesne assignments,

to The Hydraulic Press Corporation, Inc., Wilmington, Del., a corporation of Delaware Application June 15;

4 Claims.

This invention relates to presses and, in parplished mechanically by means of toggle connec-' tions, but wherein the application of power to the toggle connection is accomplished by a hydraulic cylinder-and-piston assembly.

Another object is to provide such a press wherein the toggle pivots move in a substantially hori- -zontal position, but wherein the actuating-hydraulic plunger moves in a substantially vertical position.

Another object is to provide a press which will have the quickness of operation of a mechanically actuated press combined with the smoothness of operation of the hydraulic press, this result being obtained by a combination of these two means of actuation.

Another object is toprovide. a hydraulicallyactuated toggle press, wherein the power of the hydraulic plunger is multiplied by its toggle connections with the platen.

In the drawings: Figure 1 is a somewhat diagrammatic front elevation, partly in section, of the" press of my invention;

Figure 2 is a front elevation of half of the press shown in Figure 1, partly in section, showing the hydraulic circuit and valves for operating the press;

Figure 3 is a side elevation of the control lever and the top of the valve casing for operating the press;

Figure 4 is a. central vertical section along the line 5-4 of Figure 1';

Figure 5 is a vertical section along the line 5-5 of Figure 1.

Hitherto hydraulic presses have been commonly employed in order to apply great pressure to work pieces within accurate limits, because the fluid.

pressure may be precisely controlled. These hydraulic presses of the prior art have been slow in their action and consequently are unsuitable for modern high speed operations. The mechanical pressesof the prior art, although operating 50 at a high speed through their cranks and/or levers are inflexible and not controllable because their cranks must make complete'revolutions and cannot be halted within" a partial revolution; fur- .ther their pressures cannot be delicately varied 55 'nor the press halted when a predetermined pres- 1934, Serial No. 130,31

(Cl. 113-38) v I I sure has been reached. The hydraulic press, therefore, has a slow but accurate and powerful movement whereas the mechanical press has a rapid but weaker and uncontrollable movement.

The present invention seeks to combine the ad-" vantages of the hydraulic press with those of the mechanical press without involving their defects.

This is 'done by operating the platen from. the

hydraulic piston through a series of toggle mem-' bers thereby giving the press a high speed of operation with the controllability afforded by the use of hydraulic pressure. Further, the press of my invention applies the force to the platen and 'to the frame respectively, at a plurality of points, over the surface of the platen, thereby distributing the thrust over widely scattered positions and eliminating the warping effects of concentrated thrusts. By this construction the platen may be lightened and its inertia correspondingly reduced, yet-the strength and'rigidity retained, thereby increasing the rapidity of action of the press without weakeningits construction.

Referring to the drawings in detail, the press of my invention consists of a frame, generally designated I, having side members 2 and a top ,connecting member 3 joining the latter. Also joining the side members 2 is a bottom connecting member 4, whose upper surface 5 is adapted to I receive the work pieces or dies used in connection with the operation of the press.

The side members 2 are machined, as at 6, to provide slides which are engaged by the machined portions I of the movable platen B; and, in their reciprocation, are retained in engagement by the retaining plates 9 secured to the side members 2.- v

The platen 8 is provided with a lower surface 9a adapted to receive die members or work pieces, as may be desired, these being held by devices inserted in the slots l0, corresponding to the similar slots II in the surface 5 of the lower frame cross member 4.

The platen 8 is joined to the upper cross member 3 through a toggle connection, generally des ignated l2. The toggle connection I! consists of the lower links l3, pivotally connected to the platen 8, as at H, and pivotally connected to the cross link l5, as at It (Figure 1). -Also pivotally connected to the pivot pins l6 are the upper links l1, having the pivotal connections I8 to the upper cross member 3 of the press. The link members 13 are yoke-shaped (Figure 5) in, order to engage the "pivot pins Hi, the upper link members l1 and the cross links [5 simultaneously.

Likewise attached to the. toggle connections l2;

as to the inner pivot pins It, are the oblique links l9, which at their inner ends are pivotally connected, as at 20, to the piston rod yoke 2|. The latter is provided with a bore 22, which encircles a piston rod 23 and is held against the abutment 24 thereof by the collar 25, threaded thereon (Figure 1). The piston rod 23 continues downward in a reduced diameter portion 24a, which serves as a guide member and reciprocates in the bore socket 26 of the platen 8.

The piston rod 23, beyond its abutment 23, is connected to the piston 21, as by the threaded connection 28. The piston 21 is provided with the piston head 29, adapted to reciprocate in the cylinder bore 38 of the hydraulic cylinder 3|. The latter is provided with a removable cylinder head 32, having a port 33, giving' access to the cylnder bore 30 (Figure 1). 'The cylinder 3| also is provided, near its lower end, with a port 34 opening into the cylinder bore 30 beneath the piston head 29. The lower end of the hydraulic cylinder 3| is provided with an adjustable packing connection 35, encircling the piston 21 and preventing leakage from the cylinder bore 30. The hydraulic cylinder 3| is secured to the cross member 3 by means of the bolts 36, holding together thecorrespondingly flanged and countersunk-connection 31 thereof.

The platen 8 is guided in its vertical recipro cation by the guide rods 38 and 39 placed in front of and behind the platen respectively. These guide rods 38 and 38 slidably engage the platen 8 in the bores 40, and also the yoke 2| in the bores 3|; and are secured to the upper or crown cross member 3 above the platen 8 by the threaded connections 32 (Figure 4).

The hydraulic circuit for operating the hydraulic cylinder to cause they platen 8 to rise and fall may be of any suitable kind, as maybe desired for the particular conditions under which the press is designed to operate. One such circuit is shown in Figure'2, hut it is understood that the invention is not restricted to the use of this particular circuit, which is shown for illustrative purposes only.

The hydraulic circuit, shown in Figure 2, consists of the operating lever 30, which is pivotally supported, as at 5|, upon the bracket 32 secured to the side member 2 of the press, as at 53. The operating lever 33 has a bell crank portion 33 '(Figure 3), pivotally connected by the link 33 and the pivot pins 53 and 31 to the valve connecting rod 58. The latter is connected to the reciprocable valve member 33, which is mounted to reciprocate within the bore 33 of the valve chamber 3|. r

The .valve member, generally designated 33, consists of the three spaced heads 32, 33, and 64, joined by the connecting neck 33, having the longitudinal bore 33 and transverse bores 31 and 38 therethrough. The valve chamber 3| is provided with suitably disposed ports 33, 13, II, I2, 13, and I4. The ports I2, I3 and I3 are connected to the conduit 15, leading to the tank I3 forming the fluid supply for the hydraulic pump II. The port II is provided with the conduit I3, leading to the lower port 33 in the hydraulic cylinder 3| (Figure 2) whereas the port 33 has the conduit I9, leading to the upper port 33 thereof; The conduit I8 and I9 are provided with the high pressure relief valves 33 and 8| respectively, these being designed to discharge the fluid therein through the relief conduits 82 and 83 into the conduits, I5, leading to the tank I3, when the pressure, within the conduits 13 or Kd8 valve head 33 to uncover the port II.

the predetermined pressure for which the relief valves 88 and 8| are designed to be released. The port Iii of the valve chamber 3| is connected by the conduit 83 to the outlet or pressure side of the pump 11, the intake or suction side being connected by the conduit to the fluid supply in the tank I3.

In operation, the valve member 59 is shown in its neutral position in Figure 2. When the operator faces the press (Figure 2) and .pulls the operating lever 58 toward himself, the valve member 59 rises in the valve chamber 6|. The head 62 then uncovers the port. 33, and the head 34 uncovers the port II. Pressure'fluid then flows from the pump I! through the conduit 84 and the port I0 into the valve bore 68, thence'out through port 69 and along the conduit I9 through the port 33 into the hydraulic cylinder ,3|. This causes pressure fluid to be applied to the upper side of the piston head 29.. The latter moves downward, forcing the fluid beneath it out through the port 34, the conduit I8; and the port 'I| into the lower part of the valve bore 30. This fluid passes out through the port I2 therein, and

returns to the tank 16 by way of the conduit is.

When the piston head 29 moves downward, it

likewise moves the yoke 2| downward, and the oblique links l9 move the pivot pins l3 outward. This motion, when transmitted to the toggle links I3 and II, causes the platen 8 to move downward, operating the dies or compressing the work pieces in the manner desired.

To reverse the press, the operator pushes the operating lever 30 away fromhimself, thus lowering the valve member 39. This causes the valve head 32 to uncover the port 33 and-the Pressure fluid then flows from the pump 1'! through the conduit 83 and the port 'Iliinto the middle portionof the-valve bore 33,thence through the bores 33, 31 and 33 of the valve member neck 33, and out through the port II and the pipe line I8. The latter conveys the pressure fluid to the cylinder bore 33 of the hydraulic cylinder 3| by way of the port 34, situated below the piston head 23 thereof. This moves the latter upward, forcing the fluid above it out through the port 33, and the conduit I3 into the valve bore 30 by way of the port 33. The fluid thus passes into theupper part of the valve bore 30 and out thi. ough the port I3 into the conduit I3, whence it returns to the tank I3. In this manner, the platen 8 is caused to move upward, and the operation of the press is thereby reversed.

. When the-platen reaches a downward position, wherein it is exerting a predetermined pressure, the relief valve 3| opens, discharging the excess fluid into the relief conduit 33 and thence into the tank I3. This prevents overloading and damage to the press or to the work articles. Similarly, the relief valve 33 serves to release the pressure fluid when the press has been reversed and the platen reaches its topmost position, the

excess fluid being discharged through the relief conduit 32 and the conduit I3 into the tank 13.

It will be understood that I desire'to compre- 7 hend within my invention such modifications as may be necessary to adapt it to varying conditions and uses.

Having thus fully described my invention, what I claim as new and Patent is:

1. In combination in. a press. a frame, a movdesire to secure by Letters able platen having a guide cavity therein, a piston, a hydraulic cylinder for said piston, a pair mately U-shaped the closed ends of said toggle members being pivotally anchored to said frame and said platen respectively, the open ends being pivotally connected, and -means connecting said toggle members to said piston, each pair of said toggle members be g interconnected by a pivotally attached mem er, said last-mentioned member being pivotally attached to a yoke piece joined to. said piston, said piston having an extended guiding portion adapted to engage and reciprocate in said guide cavity in said platen, whereby to provide the piston with additional guidance and support against deflection.

2. In combination'in a press, a frame, a movable platen, a piston, a hydraulic cylinder for said piston, a pair of upper and lower toggle members on each side of said piston, each toggle member being approximately U-shaped, the closed endsof said toggle members being pivotally anchored to said irame and said platen at spaced points respectively, the open ends being pivotally connected, and means connecting said toggle members to said piston, said platen having a guide cavity, and said piston having an extended portion engaging said guide cavity and reciprocable therein whereby to provide'additional support for said piston during the reciprocation thereof. g

3. In combination in a press, a frame, a movable platen, a piston, a hydraulic cylinder for said piston, inner and outer sets of upper and lower toggle members on each side of said pis-' ton, each toggle member being approximately U-shaped, the closed ends of said toggle members being pivotally anchored to said frame and said platen respectively, the open ends being pivotally connected, and means connecting said toggle members to said piston, said platen having a guide cavity, and said piston having; an extended portion engaging said guide cavity and reclprocable therein whereby to provide additional support for said piston during the reciprocation thereof.

4. In combination in a press, a frame, a movable platen, a hydraulic cylinder for said piston, inner and outer sets of upper andlower toggle members on each side of said piston, each toggle member being approximately U-shaped, the closed ends of, said toggle membersbeing pivotally anchored to said frame and said platen respectively, the open ends being pivotally connected, and means connecting said toggle mem- 

